Like my oven clock. Six buttons with cryptic symbols on them. You can press them, push them and hold multiple buttons together and it does different things with different equally cryptic symbols appearing on the LCD. Sometimes somebody accidently pushes a button and it gets stuck in a weird state where it refuses to cook. At least I’ve worked out the correct key combo to set the current time
Reminds me of a job I had years ago. As a massage therapist at a health club, we had a CD player in the room to play various kinds of music. The CD player died, maintenance decided to replace it with a DVD player. Mind you, DVD players do play CDs, and they were able to hook it up to the sound system in the room. The problem is that with no screen it was impossible to navigate system settings. Most CDs being less than an hour long and most massages being an hour meant we had to stop what we were doing when the music ended during the last 5-10 minutes of the massage and hit play again.
In one magic moment I managed to blindly hit the right combo of buttons on the remote to get it to loop playback, but as the player shuts off after a period of not being used, overnight the setting was forever lost.